Abstract

Fermented tea is traditionally consumed in many Asian countries. In Thailand, the product is made by anaerobic submerged fermentation of semi-mature tea leaves before being made into a ball form. This study aims to investigate the composition of health-associated bioactive compounds in fermented tea balls made from Camellia sinensis var. assamica, which is naturally grown in the forests of northern Thailand. The processing involves steaming semi-mature tea leaves followed by anaerobic fermentation in 2% NaCl solution (1:5 w/v of tea leaves solution). Levels of catechin (C), epicatechin (EC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG), gallocatechin (GC), flavonols (myricetin, quercetin, and kaempferol), phenolic acids (caffeic acid, chlorogenic acid, coumaric acid, and sinapic acid), total phenolic content, and in vitro antioxidant activity were evaluated in fresh tea leaves, steamed tea leaves, and fermented tea leaves over a period of 60 days’ monitoring. The results indicated that fermented tea balls still contain significant amounts of tea polyphenols, although their processing may result in some loss of most bioactive compounds. The antioxidant activity measured by Ferric Reducing Antioxidant Power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and Oxygen Radical Absorbance Capacity (ORAC) assays also declined as the fermentation time was extended. However, phenolic acids, including caffeic acid and sinapic acid, contrastingly increased during prolonged fermentation by 74.35% and 171.43% from fresh leaves, respectively.

Highlights

  • Assam tea, belonging to Camellia sinensis var. assamica, is one of the major tea varieties produced in many parts of the world

  • This paper presents the levels of total phenolic and antioxidant activity as well as polyphenol components that existed during a fermentation period of 60 days

  • This paper investigated polyphenol content during the processing of a fermented Assam tea ball

Read more

Summary

Introduction

Assam tea, belonging to Camellia sinensis var. assamica, is one of the major tea varieties produced in many parts of the world. Assam tea, belonging to Camellia sinensis var. Due to its ability to grow in humid and warm areas, Assam tea is distributed in India, Southern China, and many Southeast Asian countries, including Myanmar, Laos, Vietnam, and Thailand [1]. In northern Thailand, Assam tea is grown as part of a forest, which can be recognized as an agroforestry system. The local people of northern Thailand would nib a bite of Miang and chew until its flavor becomes plain. It is socioeconomically important, as some local villagers run small household industries for fermented tea and hire people from the neighborhood to work

Objectives
Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call